Automatic lock slider for separable fasteners



April 8, 1952 B. P. LAWSON AUTOMATIC LOCK SLIDER FOR SEPARABLE FASTENERS Filed March 20, 1950 l 1U 4. 'M 4.1 M- M I 45 5v .0 20 5 37 37 5'! 0 4/\O \c l I [a L Lin,

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INVENTOR. BIIIZDSALL LAWSON ATTOBA/EY Patented Apr. 8, 1952 UNITED STATES PATENT OFFICE.

AUTOMATIC LOCK SLIDER roe SEPARABLE FASTENERS.

Application March 20, 1950, Serial No. 150,776

9 Claims.

This invention relates to slide fasteners of the type having a pair of stringers carrying cooperating interlocking teeth or scoops which are interlocked or disengaged by movement of a slider longitudinally of the stringers. More particularly, the invention is directed to improved means for locking the slider against longitudina1 movement except when the slider is intentionally moved along the stringers. a

Slide fasteners of this type comprise a pair of stringers arranged for securement to facing edges of an opening, and these stringers carry teeth along their innerv edges. The teeth are formed with cooperating abutments and recesses which, when properly interengaged, lock the two stringers to each other to close the opening. Locking and unlocking of the teeth is eifected by moving a slider along the stringers, this slider having a Y-shaped channel receiving the teeth.

The teeth of each stringer move along separate arms of the Y-channel toward and away from the common leg of the Y. The channel is so shaped as to cam the teeth into interlocking relation in the common leg of the Y, when the slider is moved in one direction along the stringers, and to cam the teeth out of engagement and direct them into the separate divergent arms of the channel when the slider is moved in the opposite direction.

If no locking means is provided, the stringer teeth may be separated by exerting opposed lateral stresses on the stringers. This causes the slider to move in an opening direction. Various means have been proposed to prevent such accidental disengagement. For example, in one type of slider, a locking action is effected by the slider pull tab. In another type, the outer. edges of the divergent arms of the slider channel have notches or abutments to engage the outer edges of the teeth, when opposed lateral stresses are-exerted on the stringers, to lock the slider and teeth against relative longitudinal movement.

The present invention provides a slider of the latter type in which the hooks or notches of the slider channel are automatically engaged by the outer ends of the teeth whenever no pulling stress is exerted on the slider. However, a pull on the slider in either the opening or closing direction automatically releases the outer edges of the teeth from the channel hooks.

To this end, the upper ends of the outer walls of. the two divergent arms of the Y-channel are formed with hooks or abutments projecting into the channel arms. Immediately inward of the hooks, the outer, walls are recessed to receive the outer ends of the teeth, the surfaces of the hooks adjacent the recess being substantially perpendicular to the direction of travel of the teeth along the arms of the .Y-channel. The outer surfaces of the hooks are curved inwardly to provide camming surfaces for the teeth when the latter move-into the channel arms. V a

The inner walls of the divergentarms of .the channel are formed by a commonmembeinextending transversely between the slider front and rear walls, such common member comprising a triangularly-shaped post interposed. between said walls or comprising a V-notch formed on the end wall extending between and integral with said front and rear walls. In accordance with the invention, this common member or v-notch post, is embraced by a substantially heart-shaped spring of resilient flat strip material, the sprin having hooked outer ends engaged in a central groove in the outer edge thereof.

In one embodiment of the invention, an insert of rubber or other resiliently compressible material is placed between the inner edge defining the apex of the post and the inner surface-pfthe apex end of the spring. Normally, this insert expands to spread the spring to urge the teeth outwardly into the aforementioned recesses to abut the hooks, thus locking the slider against movement. When a pull is exerted on the slider in an opening direction, the stress on the post compresses the insert due to the teeth engaging the spring. Thus, the spring is forced inwardly toward the post, leaving suflicient clearance in the channel arms for the teeth to clear the hooks. When the slider is pulled in a closing direction, the teeth moving inwardly over the cam surfaces of the hooks flex the spring so that the teeth pass easily over the hook and into the channel.v In another embodiment of the invention; the spring is reversed in position and formed with a re-entrant bend received in the groove in the outer edge of the post,'and the inner ends of the spring are looped back on themselves and inter-'- engaged. These interengagedlooped ends per-L form the same function as the rubber or rubberlike insert described above, and the slider operates in the same manner asdescribed.

With the foregoing in mind, it is an object of the present invention to provide animproved self locking slider for a slide fastener.

Another object is to provide such a slider which is automatically locked whenever there is no stress on the slider and automatically unlocked whenever the slider is pulled in either the open ing or the closing direction.

pulled in an opening direction, and pulled in a closing direction; and

Fig. 8 is a view similar to Fig. 1 of a modified form of the invention slider.

Referring to Figs. 1 through 7, the invention is illustrated as incorporated in a slider l arrangedto move along .cooperable stringersZO, arranged to besecured on the oppositesides of an opening. Stringers 20, 20 in the usual manner of separable slide fasteners, carry interengageable teeth-30, .30 in theshape .of rigid elements, preferably of *metal, extending transversely of the stringers. The juxtaposed ends of the teeth are formed :withabutments v3 I -3 l on .theirupper surfaces .arranged to engage in recesses .(not shown)'.in:thelower.isurfaces of cooperating jteeth when the .two stringers are moved .into locking relation :by slider l0.

:Slider In .comprises front and rear walls or wings I l and 12 integrally interconnected-at one end .by:a V-notchedpost I3'having a groove I4 along its outer edge. The longitudinal edges of wingslland I 2 are flanged as at I6, I6 :and I1, l lbrespectively. .Ihewings H and I2 are parallel and so related that side slots l8 are provided between flanges I6 and I1, .and between flanges l6 and l'l'yto allow passage of the slider over thescoopsor teeth of stringers 20 and 20'. Furthermore, the .flanges and post 13 are cooperativelyrelated to :form a Y-shape passage 15 for teeth 30, 30'. Passage l5 has a main,.relatively wide section orqstem and divergent branches 26,26. Teeth .and 30' move along branches 26, 26' respectively,'to enter stem 25 when slider i0 is moved inaclosing direction, and are interengaged with each other in stem '25. opening movement of slider ID, teeth 30, 30' are disengaged by the tiltingand separating action imparted-to the teeth as they move from stem .25'into branches 26, 26 respectively.

In :accordance with the invention, "the outer ends of the flanges bounding wings I I and 12 are formed with hooks or projections 35, :on their surfaces defining branches'26, 26'.. Immediately inwardly 0f the hook, 'each flange has a recess 36,736 defining therewith a notch; thesurfa-ce of the hook adjacent this recess being :parallel to teeth 30,130. The outer end of eachhook is curvedinwardly toward the associated branch to form a cam surface 31, 31.

To force the teeth ;into recesses 36, .36, and

to engage beneath hooks 35, 35' of the notches,

a heart-shaped spring 40 (Fig. 3) embraces post l3. The hooked ends 4| of spring 40 engage in groove l4, andaninsert 45, of rubber or similar elastic compressible material, is placed within spring 40 between post l3 and the inner end 42 of thespring.

.The action of the described arrangement will be clear from reference :to Figs. 5, 6 and 7. In Fig. 5, slider I 0 is at rest,.and the expansive-force During of insert 45 forces spring 40 against the ends of teeth 30, 30 to bias these teeth toward the ribs [6, l6 respectively. As shown, one tooth 30 is engaged in recess 36 beneath hook 35. The fastener is thus locked against accidental opening, as by opposed lateral stresses on stringers 20, 20 as engagement of hook 35 with the outer end of a tooth 36 prevents movement of slider ID in an opening direction.

When the slider is intentionally moved in an opening direction, as by a downward pull on tab attached to rail 5| on wall H, the conditions are as shown in Fig. 6. The pull on slider l0 effects a compression of insert 45 so that the walls of spring-Mare moved toward post 13. This leaves sufficient clearance between spring 40 and hooks 35, 35' for teeth 30, 30' to clear the hooks in moving outwardly along branches 26, 26'.

When the slider I0 is pulled upwardly, or in a closing direction as shown in Fig. 7, teeth 30, 30' move inwardly along branches 26, '26. As

eachtooth enters the branch, its outer end rides over .thehook cam surface 31, 3'1 forcing spring inwardly so that the teeth can clear thejhook. Thus,;slider lfl can be pulled without restriction in either direction, but is automatically clocked when no pull is exerted on the slider.

.Fig. 8 shows a modifiedform of the invention in which a strip metal spring hasare-entrant .ben'd 6| .engaged in groove l4 and a pair of .looped ends 62. Ends 62 extend inwardly of post I13 and the loops form compressible elastic means. Loops 62 perform the same function as insert 45,.biasing teeth 30, 60' outwardly whenrslider i0 is at :rest, and being compressed by an opening pull ontheslider to allow the teeth to-pass hooks 3.5, 35f.

.Although the post l3 in the embodiments:here- .in described .is illustrated .as being .substantially triangular or V-.notched, and although the spring 40 .in the embodiment of Figs. 1 to 7 ,and'the spring'fiflin the embodiment of Fig. 8 .areillustratedas'having respectively, the free ends 4| .anchoredwithin, or a re-entrant bend 6| engaged withinthe groove [4 of theipost, it is within:.the

province of this invention to make the .post of any shape for cooperation with the flanged wings .to provide the Y"'passage:for the scoops to :interlock and separate the same, so long as thespring 40 .or'fifl .is anchored thereon, and .the contour. of the :spring 'is .such as willprovide the V-boundaries in the Y passage, and will contact the free edges of the scoops during the .movement of .the cooperatingstringers through the Y passageway.

While specific embodiments of the invention have been shown anddescribed in detailto illustrate the :application of the invention principles. it should be understood that the :invention may be otherwise :embodied without departing from :such principles.

What is claimed is:

1. In a slide fastener, a pair of stringers "having spaced :fastener elements along their adjacent longitudinal edges, -a channelled slider:.movable along said stringers to engage and disengage said :fastener elements, said slider .having at least one notch formed in one'end wall thereof for receiving one of :said fastener elements at any'point in the travel of saidslider, to lock .the slider against movement relative to said stringers, .a post in said slider for defining the channels .thereof through which the stringers pass, and hat spring biasing-means embraceably mounted on said post andcontinually bearing against the fastener elements .of said stringers for urging said fastener elements passing therethrough toward said wall and into said notch, said means having suflicient resiliency to be displaceable against the biasing action thereof by the said fastener elements during movement of the slider in either direction.

2. In a separable fastener comprising a pair of stringers carrying transversely extending interengageable teeth, a slider movable along the stringers to engage and disengage said teeth, said slider comprising spaced front and rear walls, said walls having longitudinally extending marginal walls defining a Y channel for the teeth including a main stem and a pair of divergent branches, and a post interconnecting said walls at one end thereof and lying between said branches and commonly defining the inner edges of the latter; each marginal wall, adjacent the outer end of a branch, being recessed on its inner surface to form the inner surface of a hook arranged to engage the outer ends of teeth passing outwardly through the branch and the outer end of each wall being curved inwardly toward the branch to provide a cam surface on the hook arranged to engage the outer ends of teeth entering the branch to cam the teeth toward said post, and resilient means comprising a flat spring embraceably mounted on said post and continually bearing against the inner ends of the stringer teeth passing through the branches to bias the teeth into the recesses to lock the slider against movement in an opening direction, said resilient means being compressed by the teeth, when the slider is drawn in an opening direction, to provide clearance in the branches for passage of I the teeth between said resilient means and the marginal walls, said cam surface, when said slider is drawn in a closing direction, forcing said teeth toward said post to compress said resilient means.

3. A separable fastener slider as claimed in claim 2 in which said resilient means comprises a fiat annular spring embracing said post and having portions lying in the branches and spaced from the post.

4. A separable fastener slider as claimed in claim 2, in which said resilient means comprises a fiat spring embracing said post and engaged in a groove extending longitudinally of the outer surface of said post, the remainder of the spring being spaced from said post.

5. A separable fastener slider as claimed in claim 2, in which said resilient means comprises a flat spring embracing said post and engaged in a groove extending longitudinally of the outer surface of said post, the remainder of the spring being spaced from said post, and compressible elastic means associated with the inner portion of said spring and biasing the spring toward said hooks.

6. A separable fastener slider as claimed in claim 2, in which said resilient means comprises a flat spring embracing said post and having hookedends engaged in a groove extending 10ngitudinally of the outer surface of said post, the remainder of the spring being spaced from said post, and an insert of compressible elastic material disposed between said post and the inner portion of said spring, and biasing the spring toward said hooks.

7. A separable fastener slider as claimed in claim 2, in which said resilient means comprises a fiat spring embracing said post and having hooked ends engaged in a groove extending longitudinally of the outer surface of said post, the remainder of the spring being spaced from said post, and an insert of rubber disposed between said post and the inner portion of said spring and biasing the spring toward said hooks.

8. A separable fastener slider as claimed in .claim 2, in which said resilient means comprises.

a flat spring embracing said post and having a re-entrant intermediate portion engaged in a groove extending longitudinally of the outer surface of said post, the remainder of the spring being spaced from said post.

9. A separable fastener slider as claimed in claim 2, in which said resilient means comprises a flat spring embracing said post and having a re-entrant intermediate portion engaged in a groove extending longitudinally of the outer surface of said post, the remainder of the spring being spaced from said post, and looped ends interengageable inwardly of said post to form elastic means biasing the spring toward said hooks.

BIRDSALL P. LAWSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

